Tuesday 27 April 2010 14.09 EDT
First published on Tuesday 27 April 2010 14.09 EDT

So low has the prestige of British local government fallen that the authority commanded by the London county council in the 1950s can now hardly be imagined. "Don't you know the LCC has a budget larger than the Netherlands?" fumed its deputy housing architect, Kenneth Campbell, when clashing with Evelyn Sharp, permanent secretary of the housing ministry, over some grand scheme.

The architects' department at the LCC was then the biggest design office in the world. Buoyed up by faith in the welfare state and public initiative, young architects flocked to join. Replanning and rehousing postwar London brought testing but rewarding jobs in profusion. Work never had to be touted for. No sooner had one big housing estate left the drawing board than another replaced it. Yet the atmosphere was liberal, sometimes combative. Uniformity of style was shunned, and groups could test out their design ideas – at least as far as "committee stage". The department was effectively a finishing school where many of the brightest British architects did a stint.

HJ Whitfield Lewis, who has died aged 98, presided genially over the housing section from 1950 until 1959. The position, a new one, fell to him when Sir Robert Matthew, the LCC's canny chief architect, plotted to wrest control of housing design and production from the council's valuer, in whom it had been vested during the war. With his connivance, the housing designed under the valuer was criticised in the media and Matthew had to create the bones of a new section in his department. Lewis was offered the job of deputy housing architect, but would not take it unless he knew who his boss was. To get over the problem, he was appointed to the senior post.

Lewis built up the section fast and informally, pulling in any architect of flair he could find. Soon, notable schemes such as the mixed development Ackroydon estate, Wimbledon and the two Alton estates at Roehampton were on their way, drawing plaudits from around the world for the revived ambitions of LCC housing. "Whit", as he was universally known, was too busy to do much architecture, but he managed the link between the youthful, often restive design teams and his successive chiefs – Matthew, Leslie Martin and Hubert Bennett – with enthusiasm and aplomb.

Lewis arrived at the LCC with a solid modernist pedigree. Chepstow-born, he went to Monmouth school in south-east Wales before moving to Cardiff to train at the Welsh School of Architecture. In 1932, he moved to London to work first with Joseph Emberton, followed by Sydney Trent, designer of the Gaumont cinemas. His initiation into the avant garde came when he transferred to the office of Mendelsohn and Chermayeff. There his jobs included the Gilbey offices at Camden Town, and Chermayeff's own timber house at Halland, Sussex. In the run-up to war, Lewis worked with Norman and Dawbarn, specialists in buildings for the aviation industry. He spent the war as a technician and designer for the aircraft makers Short Brothers at Rochester, then returned to Norman and Dawbarn to spearhead their diversification into public housing. Their St Pancras Way estate (again in Camden) opened in 1948: largely Lewis's design, it won awards and became his springboard into the LCC.

Once ensconced within the public sector, Lewis stayed there. Like many architects of his day, he was a liberal communist until he and his wife Barbara seceded from the party as "Tito-ist deviationists". Matthew had to fend off trouble over his staff's affiliations, but these hardly affected Lewis's prospects. In 1959, he was appointed Middlesex county council's chief architect. He had shortlived success in applying LCC-style policies to the different portfolio of work available there, bringing in young architects and farming out schools to good private firms. But Middlesex was not destined to survive the reorganisation of London government.

His last full-time job was as chief architect to the Ministry of Housing and Local Government, later the Department of the Environment (1964–71). These were the years when public housing seemed to have gone painfully awry. His tasks in central government could seldom be called creative, and Lewis sometimes described himself ruefully as a "clerkitect". Latterly he acted as a consultant for the architects Clifford Culpin and Partners.

Lewis was as debonair and as engaging in private life as in his profession. A natural craftsman, he made furniture, boats and even an organ, and was a good amateur musician. In architecture his tastes leant towards Scandinavia and Frank Lloyd Wright rather than Le Corbusier, whom many leftwing architects of his generation dismissed as a stylist and therefore a reactionary. There was nothing Whit enjoyed more than a hearty argument with earnest young Corbusians.

He was married three times. With his first wife, Yoanna, he adopted two children, David and Bronwen. After her death he married Barbara Watt, an architect who worked with Yorke, Rosenberg and Mardall. With her he had two further children, Victoria and Polly. Later he married Pamela Leaford. Pamela, Barbara, David, Victoria and Polly survive him.

• Herbert John Whitfield Lewis, architect, born 9 April 1911; died 29 March 2010